Time-kill curve analysis and pharmacodynamic modelling for in vitro evaluation of antimicrobials against Neisseria gonorrhoeae

Table 1 Parameter estimates of the pharmacodynamic function for nine antimicrobials in the antimicrobial susceptible Neisseria gonorrhoeae strain DG666

Antimicrobial	Antimicrobial class	к ^a	ψ _min (h⁻¹)^a	ψ _max (h⁻¹)^a	zMIC (μg/ml)^a	MIC (μg/ml)^b
Ciprofloxacin	Fluoroquinolone	1.1 ± 0.1	−8.9 ± 2.2	0.7 ± 0.4	0.002 ± 0.0001	<0.004
Gentamicin	Aminoglycoside	1.0 ± 0.2	−106.9 ± 140^c	0.9 ± 0.07	0.2 ± 0.04	1
Spectinomycin	Aminocyclitol	2.0 ± 0.6	−9.6 ± 1	0.7 ± 0.03	5 ± 0.7	4
Azithromycin	Macrolide	2.5 ± 0.1	−2.2 ± 0.1	0.6 ± 0.05	0.03 ± 0.002	0.19
Benzylpenicillin	β-lactam	1.1 ± 0.1	−1.6 ± 0.6	0.9 ± 0.2	0.004 ± 0.002	0.032
Ceftriaxone	β-lactam	1.6 ± 0.1	−0.6 ± 0.2	0.8 ± 0.07	0.0003 ± 0.0001	<0.002
Cefixime	β-lactam	1.7 ± 0.5	−0.8 ± 0.2	0.8 ± 0.1	0.0002 ± 0.0002	0.016
Chloramphenicol	Chloramphenicol	1.8 ± 0.4	−0.1 ± 0.01	0.7 ± 0.2	0.5 ± 0.1	0.19
Tetracycline	Tetracycline	1.0 ± 0.2	−0.2 ± 0.08	0.8 ± 0.07	0.5 ± 0.3	0.125

^aEstimates are given as arithmetic means and standard deviations from two independent experiments. Parameter estimates for each individual experiment are given in Additional file 1: Table S1
^bMIC values measured with Etest in accordance with the manufacturer’s instructions
^cParameter below limit of detection

ISSN: 1471-2180